Tools for forming decorative patterns in concrete to provide the appearance of brick, cobblestone, slate, stone, tile and wood have gained in popularity in recent years. There are a number of advantages to using such tools in concrete as opposed to the authentic hand-laid materials. First, the cost of materials and labor to imprint the pattern in a bed of concrete is greatly reduced from that of laying real stone or brick. In addition, the concrete provides an extremely durable and lasting surface when cured. Independent hand-laid stones or bricks have gaps in between which, despite being filled with mortar, may cause them to settle to result in a uneven surface. Finally, a solid layer of concrete prevents the disruptive, unsightly upgrowth of weeds or other vegetation which inevitably occurs with separate stones or bricks.
There are two general classes of tools for forming decorative patterns in concrete. A first type simply forms decorative grout lines and is embodied in U.S. Pat. No. 4,135,840 issued to Puccini et al. This patent discloses a tool for printing non-repeating false stone outline patterns in concrete. The blades of the tool used to form the grout lines between the false stones all terminate at identical locations on each of the four sides around the generally square tool. Thus, the terminal ends of each blade line up with the extending terminal ends of the blades of another tool, or with the first tool rotated. However, this type of tool cannot imprint a textured surface in the concrete and depends on the absence of a peripheral border line to ensure the random appearance of a plurality of side-by-side patterns.
The second class of tools include an outer border surrounding a textured surface which is pressed into the concrete to give a three-dimensional appearance to the concrete. Typically, the region within the outer border is divided by a grout line pattern to delineate simulated stones. The tools usually include one or more handles on the rear side so that the imprint may be pressed down and the tool subsequently lifted. One example of such a tool for forming a decorative impression in concrete is shown in U.S. Pat. No. 5,061,172, issued to Fennessy, Sr. This patent discloses a generally square forming tool having a cutout in one corner so that adjacent rows of tools may be laid down on the concrete at a slight offset. Each tool must be oriented with the cutout at the same corner for the tools to fit together. This type of tool is seen in the prior art illustrations of FIGS. 1-6.
The biggest problem aesthetically with prior texturing tools has been the frequent positioning of two or more of the same tool patterns in close proximity, thus creating a repetitive appearance which, if noticed, reveals the false stones for what they are. Because tools such as those of Fennessy, Sr. cannot be rotated, each individual tool can only form one grout line pattern from the vantage point of a fixed observer. A random appearance is thus unavailable unless a large number of tools are used having different inner grout line patterns. However, the use of a large number of tools is costly and also awkward as the tools weigh quite a great deal and must be transported and laboriously installed on the concrete.
A number of concrete texturing tools have been developed by Precision Stamped Concrete Tools of Pico Rivera, Calif. Some of the tools developed generally have an outer border having a shape which can be closely fitted together with all of the surrounding shapes to together form the desired pattern. When imprinting a pattern of random stone in concrete, for example, Matcrete has designed a tool having six outwardly extending portions which are capable of mating with adjacent tools in any of six orientations. While this is a great advantage for random stone patterns, popular rectilinear simulated stones such as Ashler slam cannot be fitted within such an irregular outer border.
To date, there is a need for an improved forming tool for reproducing the look of stones such as Ashler slate which provides a more random final appearance.